1. Field of the Invention
The present invention relates to the “art” of making snow. More particularly, it relates to improvements by which conventional snow-making devices, i.e., “snow-guns”, are rendered more efficient in terms of requiring less compressed air to produce a given amount of snow.
2. The Prior Art
In the commonly assigned U.S. Pat. No. 3,829,013 issued to H. Ronald Ratnik, a snow-gun is disclosed that is adapted to produce a multitude of ice crystals resembling natural snow from a mixture of pressurized water and compressed air. Such a device (shown in FIGS. 1 and 2) operates by injecting water from a pressurized source (e.g., between 60 and 120 pounds per square inch (PSI)) radially inwardly through a plurality of equally spaced holes circumferentially located in the wall of a cylindrical conduit through which air is flowing from a compressed air source at a high flow rate (e.g., between 400 and 900 cubic feet per minute (CFM)). The respective holes in the conduit wall are typically between ¼ and ⅛ inch in diameter, and each hole serves to break-up the water passing through it into relatively small droplets, between 100 and 300 microns in diameter. The air rushing through the conduit serves to carry the droplet and water mixture into contact with a concave anvil or “cup” axially located on the longitudinal axis of the conduit, a short distance from the outlet end of the conduit. Upon impacting the cup, the water droplets are further broken-up and reduced in size (e.g., to between 50 and 100 microns). Upon reflecting from the concave surface of the cup, the atomized mixture of air and water enters a mixing chamber within the forward portion of the gun. The mixing chamber is of significantly larger volume than the cup, and the water particles entering the mixing chamber are cooled appreciably by the cooler ambient temperature therein. The water particles are then further cooled as they exit the mixing chamber and expand into the surrounding atmosphere through a circular or oval-shaped aperture formed in a nozzle carried by the forward-most wall of the snow gun.
For decades, snow-guns of the type described above have been used commercially at ski resorts and the like for supplementing the amount of natural snow-fall received at these areas. Indeed, it is not uncommon for such snow-guns to provide the majority of snow on the ground at these resorts. In addition to the initial cost of the snow-guns, the most significant expense in making snow “artificially” is the cost to the compressed-air component. The need to transport compressed air up a mountain side from a base unit situated at the bottom of the mountain to a multitude of snow-guns situated at various levels on the mountain readily translates into a certain amount of horsepower which, in turn, translates into Kilowatt hours of electrical energy and, hence, financial outlay. Thus, any significant reduction in the amount of compressed air required to produce a nominal amount of snow is greeted with great enthusiasm by the owners and operators of these facilities.
As indicated above, snow-making is more of an art-form than science. Why a particular snow-gun design “works” well (or poorly) is not totally understood. Where, during the design phase, major modifications are expected to enhance the snow-making efficiency of a snow-gun, actual testing in the field has often proven the designers to be wrong. And vice-versa, i.e., where seemingly minor or trivial changes in a design are expected to have little or no effect on performance and efficiency of a given snow-gun, field-testing has yielded totally unexpected significant increases in output and efficiency of the snow-gun. The invention described herein is an example of the latter situation.